Monoprice offers its Monoprice Over-Ear Headphones, model no. 108323, for $19.90 with free shipping. That's $3 under our April mention and the lowest total price we could find by $13. These well-reviewed headphones feature 50mm drivers, 20Hz to 20kHz frequency response, and detachable 11.5-foot and 50" cables that connect to the headphones via a 3.5mm input.
Update: Specs corrected.